It makes for a grabby headline, but are gay men really more likely to develop cancer? A new study published in the journal Cancer found that gay men were nearly twice as likely to report a diagnosis of cancer than straight men. But why?

The study did not answer that question. It’s not clear, for instance, whether gay men were more likely to develop cancer than straight men, whether they were more likely to be diagnosed, or whether they more likely to survive and report it.

Similar data in women found no difference in cancer rates by sexual orientation; however, the study did find that lesbian and bisexual cancer survivors were more likely to self-report poor or fair health than heterosexual women. Self-reported health status did not differ by sexual orientation in men.

Researchers led by Ulrike Boehmer of the Boston University School of Public Health analyzed three years of data on more than 120,000 adults who filled out the California Health Interview survey. Among other questions, the respondents were asked about their sexual orientation and whether they had ever been diagnosed with cancer.

Out of 51,000 men, about 3,690 reported having had cancer: they accounted for 8% of gay men and 5% of straight men; the increase in risk in gay men was not attributable to other factors like race, income level or age.

Among 71,000 women, 7,252 reported a cancer diagnosis, but the rate of diagnosis was the same regardless of sexual orientation. But women who identified as lesbian or bisexual were more than twice as likely to report fair or poor health than straight women after surviving cancer.

Again, the study didn’t delve into the reasons for the disparities in rates of cancer diagnosis, but the authors said the gay community is more vulnerable to certain cancer risk factors. For instance, both gay men and lesbian women are more likely to smoke and abuse alcohol than their straight peers — these are known contributors to cancer.

Gays and lesbians are also less likely to get routine cancer screening and check-ups because of perceived discrimination from doctors, said Liz Margolies, executive director of the National LGBT Cancer Network.

The higher rates of HIV infection in gay men than in straight men could also help explain the difference: HIV-positive patients have a higher risk of anal, lung and testicular cancers and Hodgkin’s lymphoma (HIV status was outside the scope of the study, however).

Another factor that may affect health in the LGBT community is “minority stress,” lead author Boehmer said, referring to the psychological strain endured by minority groups as a result of prejudice or discrimination. MyHealthNewsDaily reported:

“It’s been my experience that the lower quality of life that lesbians report after a cancer diagnosis does not reveal as much about the particular diagnosis, but more about our life experience in general, particularly when confronting a major life crisis” like a cancer diagnosis, a relationship change or a job loss, said Linda Ellis, executive director of the Atlanta Lesbian Health Initiative in Georgia, who was not involved with the study.

It’s not that lesbian or bisexual women walk around more depressed than their straight peers, Ellis said. But coming out to each new person, whether it’s the new nurse in the chemo clinic or the members of the cancer support group, takes a lot of energy, she said. … In addition, it’s not unusual for lesbian or bisexual women to have severed ties with family, so a person’s natural circle of support may be weakened, she said.

The current was not designed to measure potential contributors to cancer and health risks in the LGBT community. But the findings suggest that public-health officials need to pay more attention to the gay, lesbian and bisexual population — particularly when it comes to cancer prevention and screening.

In April, an Institute of Medicine report proposed including sexual orientation information in medical records and in government studies as a way to increase understanding of the health risks that may be particular to the gay and lesbian community.

“At a time when lesbian, gay, bisexual, and transgender individuals — often referred to under the umbrella acronym LGBT — are becoming more visible in society and more socially acknowledged, clinicians and researchers are faced with incomplete information about their health status,” said the report.